Method and apparatus for interaction between an edge computing system and a mobile communication network for providing edge computing service

ABSTRACT

The disclosure relates to a 5G or pre-5G communication system for supporting a higher data rate after a 4G communication system such as LTE. A method according to an embodiment of the disclosure is a control method in an edge enabler server (EES) of a mobile edge computing system, and may include subscribing to a user plane path change event at an edge application server (EAS); determining an application context relocation (ACR) based on receiving a user plane path management event notification from the mobile communication network in case of subscribing to the user plane path change event for the EAS; transmitting an ACR request message to the EAS; receiving an EAS response message from the EAS; and transmitting an application function (AF) acknowledgment message to a first node of the mobile communication network in response to receiving the EAS response message from the EAS.

TECHNICAL FIELD

The disclosure relates to a method and apparatus for providing an edgecomputing service to a user equipment in a mobile communication networkand, more particularly, to a method and apparatus for interactionsbetween an edge computing system and a mobile communication network forproviding an edge computing service.

BACKGROUND ART

To meet the demand for wireless data traffic having increased sincedeployment of 4G communication systems, efforts have been made todevelop an improved 5G or pre-5G communication system. Therefore, the 5Gor pre-5G communication system is also called a ‘Beyond 4G Network’ or a‘Post LTE System’.

The 5G communication system is considered to be implemented in higherfrequency (mmWave) bands, e.g., 60 GHz bands, so as to accomplish higherdata rates. To decrease propagation loss of the radio waves and increasethe transmission distance, the beamforming, massive multiple-inputmultiple-output (MIMO), Full Dimensional MIMO (FD-MIMO), array antenna,an analog beam forming, large scale antenna techniques are discussed in5G communication systems.

In addition, in 5G communication systems, development for system networkimprovement is under way based on an advanced small cell, a cloud radioaccess network (cloud RAN), an ultra-dense network, device-to-device(D2D) communication, a wireless backhaul, a moving network, cooperativecommunication, coordinated multi-points (CoMP), reception-endinterference cancellation, and the like.

In the 5G system, hybrid FSK and QAM modulation (FQAM) and slidingwindow superposition coding (SWSC) as an advanced coding modulation(ACM), and filter bank multi carrier (FBMC), non-orthogonal multipleaccess (NOMA), and sparse code multiple access (SCMA) as an advancedaccess technology have been developed.

The disclosure relates to a communication system, and a terminal mayestablish a data connection with an edge data network that is locatedclose to the terminal's location in order to use a low-latency orbroadband service. In an edge computing system, the terminal may beprovided with a data service by accessing an application server runningin an edge hosting environment or an edge computing platform thatoperates in an edge enabler server of the corresponding edge datanetwork. In this case, the terminal that wants to access the edgecomputing system may be a mobile communication terminal that is providedwith a mobile communication service.

In order for the mobile communication terminal to access a mobile edgecomputing (MEC) system, a procedure for interactions between the mobilecommunication network and the MEC system should be defined.

However, until now, a specific procedure for interactions between theMEC system and the mobile communication system to provide the MECservice to the mobile communication terminal has not been defined.

DISCLOSURE OF INVENTION Technical Problem

As mentioned above, the procedure for interactions between the MECsystem and the mobile communication network is not defined. Therefore,there may occur a situation in which an edge application server and anedge enabler server existing in the MEC system redundantly interact withthe mobile communication system, for example, the 3GPP network toperform the same operation. In this case, resource inefficiency may becaused due to redundant use of resources to perform the same operation.

Accordingly, in order to solve this problem, the disclosure provides amethod and apparatuses for providing a procedure for interactionsbetween the MEC system and the mobile communication system.

In addition, the disclosure provides a method in which the edge enablerserver interacts with the 3GPP network on behalf of the edge applicationserver registered therein.

The disclosure proposes a procedure for acquiring information of theedge application server required for interactions with the 3GPP networkin order to support such indirect interactions.

Also, the disclosure provides a method for the edge data network toprocess information in a form that can be used in the 3GPP network.

Further, the disclosure provides a procedure for the edge data networkto continuously provide an edge computing service by utilizinginformation acquired as a result of interactions with the 3GPP network.

Solution to Problem

According to an embodiment of the disclosure, a method for an edgeenabler server of an edge computing data network to provide an edgecomputing service to a user equipment of a mobile communication systemmay include receiving, at the edge enabler server, a registrationrequest message from an application server that provides an edgecomputing service to the user equipment, wherein the registrationrequest message includes at least one of EAS service continuitycapability/support, AF request support, traffic routing requirementinformation, EAS data network access identifier (DNAI) information, andAF transaction identifier (ID); transmitting an application function(AF) request message indicating at least one of the information to themobile communication network based on the information included in theregistration request message; searching for a target application serverfor a user plane management when receiving a message corresponding to auser plane management event of the user equipment from the mobilecommunication network; and providing the search result to the mobilecommunication network and the user equipment.

Advantageous Effects of Invention

According to the disclosure, the edge enabler server performsinteractions with the 3GPP network instead of individual edgeapplication servers, so it is possible to reduce a redundant use ofnetwork resources. Also, it is possible to support interactions betweenthe 3GPP network and the edge application server without an individualservice agreement between a mobile communication network operator and athird-party edge application server provider that is not an edgecomputing service provider (e.g., an edge enabler server provider) northe mobile communication network operator.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram illustrating a connection between a 3GPP network andan edge computing system network and a movement of a terminal accordingto the disclosure.

FIG. 2 is a diagram illustrating a structure of API-based connectionamong a user equipment, a mobile communication network, and an edgecomputing system according to an embodiment of the disclosure.

FIG. 3 is a diagram illustrating a signal flow for transferring edgeapplication information required for AF request creation andtransmission according to an embodiment of the disclosure.

FIG. 4 is a diagram illustrating a signal flow for a user plane (UP)path management event notification according to an embodiment of thedisclosure.

FIG. 5 is a diagram illustrating a signal flow for providing a userplane path management event notification message when AF acknowledgmentpreference is configured according to an embodiment of the disclosure.

FIG. 6 is a diagram illustrating a signal flow for providing a userplane path management event notification message when AF acknowledgmentpreference is configured according to an embodiment of the disclosure.

FIG. 7 is a diagram illustrating a signal flow for a T-EAS discoveryoperation based on DNAI of EES according to an embodiment of thedisclosure.

FIG. 8 is a diagram illustrating a signal flow for an operation ofDNAI-based target EAS discovery of EES according to an embodiment of thedisclosure.

FIG. 9 is a diagram illustrating a signal flow for a DNAI-basedapplication context relocation procedure according to an embodiment ofthe disclosure.

FIG. 10 is a diagram illustrating internal function blocks of an edgeapplication server or an edge enabler server according to variousembodiments of the disclosure.

MODE FOR THE INVENTION

Hereinafter, the operation principle of the disclosure will be describedin detail with reference to the accompanying drawings. Furthermore,terms to be described hereunder have been defined in consideration offunctions in the disclosure. Such terms may vary depending on a user'sor operator's intention or custom, so their definitions should bedetermined based on the contents of this specification.

In the disclosure, terms referring to network entities and entities ofan edge computing system, terms referring to messages, terms referringto identification information, etc. are exemplified for convenience ofdescription. Accordingly, the disclosure is not limited to the termsdescribed later, and other terms referring to objects having equivalenttechnical meanings may be used.

In the disclosure, terms and names defined in the 3GPP system standardare used for convenience. However, the disclosure is not limited by suchterms and names, and may be equally applied to systems complying withother standards.

The disclosure to be described hereinafter provides a method andapparatus for an edge application server of an MEC system to interworkwith a mobile communication network, for example, a 3GPP network.

In addition, the disclosure provides a method for an edge enablerserver, which serves as an application function (AF) on behalf of theedge application server of the MEC system, to define and transferinformation required for AF request execution request and AF requestcreation.

In addition, the disclosure provides a method for the edge enablerserver of the MEC system to perform AF request by transforming, orresponding to, information provided by the edge application server intothe form of information that a 3GPP network function device canunderstand.

In addition, the disclosure provides a method for the edge enablerserver to perform, based on information provided from the 3GPP networkas a result of the AF request, operations required for providing an edgecomputing service (e.g., selecting a new edge application server inresponse to a terminal movement, determining whether the edge computingservice is continuously available, or the like).

FIG. 1 is a diagram illustrating a connection between a 3GPP network andan edge computing system network and a movement of a terminal accordingto the disclosure.

Referring to FIG. 1 , a service area 1 of a mobile network operator(MNO) is illustrated. The service area 1 of the MNO may contain dividededge data networks to provide an edge computing service to an electronicdevice. Each of the edge data networks may have a region 10 or 20 forproviding the edge computing service to the electronic device (UE1) 50.For example, in FIG. 1 , the service region 10 of the first edge datanetwork contains a first base station 111, a second base station 112, athird base station 113, and a fourth base station 114, and the serviceregion 20 of the second edge data network contains a fifth base station211 and a sixth base station 212.

In the example of FIG. 1 , the service area 10 of the first edge datanetwork including the first base station 111 to the fourth base station1114 further contains two different user plane function (UPF) devices121 and 122. In the following description, the UPFs 121 and 122 may belogically understood as one network device unless otherwise specified.Therefore, in the following description, the UPFs 121 and 122 will bereferred to as ‘UPF device’ or ‘UPF’. In addition, the service region 20of the second edge data network contains only one UPF1 221, for example.As can be seen from the example of FIG. 1 , one edge data network mayhave one or more UPFs.

The service region 10 of the first edge data network may be an areamanaged by one edge enabler server 100. Also, the service region 20 ofthe second edge data network may be an area managed by another edgeenabler server 200. As such, the service regions 10 and 20 of the edgedata network may be configured as areas that can be managed by the edgeenabler servers 100 and 200. In another example, the edge data networkservice regions 10 and 20 may be defined as areas of edge applicationservers connected to the edge enabler servers 100 and 200. Also, asexemplarily shown in FIG. 1 , the service regions 10 and 20 of the edgedata network of the MEC system and the mobile communication system maybe an area (in case of reference numeral 20) capable of servicing the UE50 by at least one UPF, or an area (in case of reference numeral 10)capable of servicing the UE 50 by two or more UPFs. In case ofconnection with the mobile communication system as such, the serviceregions 10 and 20 of the edge data network of the MEC system may be inthe form of one base station area or combined two or more base stationareas. Although the service area of the edge data network is notillustrated with only one base station area in FIG. 1 , one base stationarea may be the service area of one edge data network if necessary.

As exemplarily shown in FIG. 1 , the edge enabler servers 100 and 200may be connected to or include the same or different edge applicationservers 101, 102, and 201, respectively. First edge application servers101 and 201 and a second edge application server 102 may providedifferent edge computing services, respectively. The first applicationserver 201 located in the service region 20 of the second edge datanetwork that provides the same service as the first edge applicationserver 101 located in the service region 10 of the first edge datanetwork may provide the same edge computing service to the electronicdevice 50 through different edge enabler servers 100 and 200. Asexemplarily shown in FIG. 1 , the first edge application server 101located in the service area 10 of the first edge data network mayprovide an edge computing service to the electronic device 50 connectedto any one of the base stations 111, 112, 113, and 114 located in thefirst edge data network. The second edge application server 102 mayprovide an edge computing service to the electronic device 50 connectedto any one of the base stations 111, 112, 113, and 114 located in thefirst edge data network.

The electronic device 50 may be provided with the edge computing serviceaccording to the disclosure, and may be a mobile terminal capable ofaccessing the mobile communication network through a wireless network.The electronic device 50 may include a variety of mobile electronicdevices such as a smart phone, a tablet computer, a smart watch, a gamemachine, an automobile, a motorcycle, a bicycle, an airplane, a ship,etc. and/or various types of electronic devices capable of providing anIoT service. Furthermore, in a certain case, the electronic device 50may be a device such as a personal computer (PC). In this case, the PCshould have a function to access the mobile communication network. Theelectronic device 50 may be equipped with at least one edge computingservice application 53 according to the disclosure, may include an edgeenabler client 52 according to the disclosure, and may include a mobileterminal 51 performing a wireless communication function, for example, acommunication layer.

Being equipped with the edge computing service application may mean thatan application for receiving the edge computing service may be installed(or stored) in a memory (not shown) of the electronic device 50. Also,being equipped with the edge computing service application may mean thatthe application installed in the electronic device 50 is loaded into atleast one processor to perform an operation for providing the edgecomputing service.

The edge enabler client 52 may be installed in the memory (not shown) ofthe electronic device 50 in which the application for receiving the edgecomputing service is equipped. In addition, the edge enabler client 52may mean to be loaded into at least one processor instead of theinstalled application and to perform at least some of operationsrequired by the edge computing service application.

The mobile terminal (MT) 51 may include a communication layer capable ofcommunicating with a specific wireless communication network, forexample, the 3GPP communication network in a configured manner. Thecommunication layer may include at least one communication processorand/or a modem, and may include logic for transmitting and receivingradio signals and at least one antenna.

Hereinafter, the electronic device 50 will be referred to as a userequipment (UE) for convenience of description. In addition, unlessparticularly limited, a terminal or a mobile terminal to which referencenumeral 51 is not added may be understood as an electronic device or auser equipment.

The base stations 111, 112, 113, 1113, 114, 211, and 212 have apredetermined area capable of communicating with the UE 50 in a setwireless communication scheme. For example, when the set wirelesscommunication scheme uses the scheme of the 3GPP mobile communicationnetwork, the base stations 111, 112, 113, 1113, 114, 211, and 212 may bebase stations in the 3GPP mobile communication network.

The above-described configuration of FIG. 1 exemplarily illustrates anedge computing deployment and a case of interworking with the 5G networkamong mobile communication networks.

The user plane function (UPF) devices 121, 122, and 221 may serve asgateways for transmitting packets corresponding to user data transmittedand received by the user equipment. According to an embodiment of thedisclosure, the UPFs 121, 122, and 221 may be physically and/orlogically close to the edge enabler servers 100 and 200 to support theedge computing service. Deploying the UPFs 121, 122, and 221 to bephysically and/or logically close to the edge enabler servers 100 and200 allows a data packet to be transferred directly to the edge datanetwork without passing through the Internet, thus reducing transmissiondelay. That is, low-latency transmission is possible. According toanother embodiment of the disclosure, the UPFs 121, 122, and 221 mayalso be connected to the edge enabler servers 100 and 200 via a datanetwork connected to the Internet.

According to an embodiment of the disclosure, the edge computing systemmay be composed of the edge enabler servers 100 and 200, an edgeconfiguration server or edge data network configuration server 30, theedge enabler client (EEC) 52. According to various embodiments of thedisclosure, the edge enabler servers 100 and 200 may construct an edgehosting environment or an edge computing platform. Constructing the edgehosting environment or the edge computing platform may mean that theedge enabler server and at least one edge application server areconnected or that at least one edge application server is running on acomputing platform of the edge enabler server. Therefore, the edgeenabler servers 100 and 200 may know information about the edgeapplication server running in the edge hosting environment or on theedge computing platform.

According to various embodiments of the disclosure, the edge enablerservers 100 and 200 may negotiate with the UE 50 and thereby connect theapplication client 52 running in the UE 50 and the edge applicationserver in the edge hosting environment. According to various embodimentsof the disclosure, the UE 50 that supports the edge computing system mayembed or be equipped with the edge enabler client 52 as described above.According to an embodiment of the disclosure, the negotiation betweenthe UE 50 and the edge application server may be performed throughinteractions between the edge enabler client 52 in the UE 50 and theedge enabler servers 100 and 200. According to an embodiment of thedisclosure, a layer in which interactions between the edge enablerclient 52 and the edge enabler servers 100 and 200 such as thenegotiation are performed may be referred to as an edge enabling layer.The terminal or UE 50 according to the disclosure may include an IoTdevice, a vehicle, or the like as well as the smart phone describedabove.

According to various embodiments of the disclosure, the edgeconfiguration server 30 knows deployment information of the edge enablerservers 100 and 200, and may perform a function of transmittingconfiguration information for using the edge computing service to the UE50. According to an embodiment of the disclosure, the configurationinformation may include at least one of edge data network connectioninformation, edge data network service area information, and edgeenabler server connection information. Without defining the edge datanetwork separately, it can be seen that a local data network in whichthe edge enabler server and the edge application server are presentcorresponds to the edge data network. The edge configuration server maybe referred to as ECS 30.

According to various embodiments of the disclosure, the edge datanetwork connection information may include, for example, informationsuch as a data network name and single-network slice selectionassistance information (S-NSSAI). The network slice means that a device(or server) performing a specific function may be implemented in theform of a slice in a core network. For example, the UPF may beimplemented as one server or network device. In another example, oneserver or network device may have two or more UPF slices therein. Instill another example, the UPF may be implemented with two or moreservers or may be implemented with two or more network devices. Aspecific network slice may be understood as a network device thatperforms one specific function logically.

According to various embodiments of the disclosure, the edge datanetwork service area (region) may be, for example, at least one of orinclude two or more of a cell list, a list of tracking areas, and anetwork identifier (PLMN ID) of an operator. Also, the edge data networkservice area (region) may be a service area (region) of the edge enablerserver that is set by the edge enabler server in the edge data network.Alternatively, in case of an edge data network deployment scenario usinga local access data network (LADN), the edge data network area (region)may be the same as the LADN service area. That is, the UE 50 mayreceive, from the edge configuration server 30, information of the edgeenabler server accessible at a specific location. If the edgeconfiguration server 30 can know information about the edge applicationserver running in the edge hosting environment of a specific edgeenabler server, the edge enabler client 52 in the UE 50 can obtain thecorresponding information from the edge configuration server 30.According to various embodiments of the disclosure, the edge enablerserver connection information may be, for example, an endpoint addresssuch as a uniform resource identifier (URI) or an Internet protocol (IP)address.

According to various embodiments of the disclosure, the UE 50 mayreceive information about an accessible edge enabler server from theedge configuration server 30, based on information such as a specificlocation, for example, a specific base station, a specific data network,or a specific physical location. According to an embodiment of thedisclosure, if the edge configuration server 30 can know informationabout the edge application server running in the edge hostingenvironment of a specific edge enabler server, the UE 50 can also obtainthe corresponding information through the edge enabler client 52.

According to various embodiments of the disclosure, the edge applicationservers 101, 102, and 201 may refer to third-party application serversrunning in the edge computing system. According to an embodiment of thedisclosure, the edge application servers 101, 102, and 201 may bethird-party application servers running on an infrastructure provided bythe edge hosting environment, and may provide a low-latency service atlocations close to the UE 50. According to various embodiments of thedisclosure, information about an upper layer of a service provided tothe UE 50 by the edge application server may be referred to as anapplication context. For example, when a user uses a real-time gameapplication, all information necessary to regenerate a screen and a playphase currently viewed by the user in the game may be included in theapplication context. For example, in order for the UE 50 to use theexisting service without interruption through connection to another edgeapplication server, the application context should be relocated to theedge application server to be newly connected. In order to performapplication context relocation, an edge application server capable ofproviding a service to an application running in the application client53 of the UE 50 should be available. Availability of the edgeapplication server in the edge data network may be determined dependingon whether the edge application server is driven in the edge hostingenvironment, on the state of the edge application server, and the like.

In the edge computing system, the edge enabler servers 100 and 200, theedge application servers 101, 102, and 201, and the edge configurationserver 30 can acquire terminal-related information from the mobilecommunication system. Specifically, for example, the 3GPP system mayinclude a network exposure function (NEF) device which is a networkentity that exposes a network function. In this case, at least one ofentities constituting the edge computing system may include anapplication program interface (API). The entity of the edge computingsystem including the API may acquire terminal-related information byusing the API.

According to various embodiments of the disclosure, as described above,the UE 50 may contain therein the application client 53, the edgeenabler client 52 that enables the application client 53 to interactwith the edge computing service, and the mobile terminal (MT) 51 thataccesses the mobile communication system. According to variousembodiments of the disclosure, an application of the UE 50 is anapplication provided by a third party and may refer to a clientapplication program running in the UE 50 for a specific applicationservice. Two or more applications may be running in the UE 50. Accordingto an embodiment of the disclosure, at least one of these applicationsmay use a multi-access edge computing (MEC) service. The edge enablerclient 52 in the UE 50 may refer to a client that performs an operationin the UE 50 necessary for using the MEC service. According to anembodiment of the disclosure, the edge enabler client 52 may performoperations of identifying which application can use the edge computingservice, and connecting the network interface such that data of theapplication client of the UE 50 can be transmitted to the edgeapplication server providing the edge computing service. According to anembodiment of the disclosure, the UE 50 may establish a radio channelwith the base station through the MT 51 in order to use the edgecomputing service. Establishing the radio channel may be performed in acommunication layer of the MT 51, for example, a 3GPP communicationlayer. According to an embodiment of the disclosure, the communicationlayer of the MT 51 may establish a radio connection for datacommunication, register the UE 50 in the mobile communication system,establish a connection for data transmission to the mobile communicationsystem, and transmit/receive data.

Meanwhile, the network functions (NFs) running in the 3GPP networkillustrated in FIG. 1 or to be described below will be described as“devices”. However, in actual implementation, each of the NFs may beimplemented in the form of an instance in a single physical server.

In the disclosure, one instance may be implemented as specific software,and the software performing one instance operation may be implemented torun in one physical hardware device.

According to another embodiment of the disclosure, one instance may berunning in two or more hardware servers rather than one physicalhardware device, for example, two or more servers, or different racksconstituting one server.

According to still another embodiment of the disclosure, two or moredifferent instances may be running in one physical hardware device, forexample, one server. In this case, at least some of the NFs illustratedin FIG. 1 may be running in the same physical hardware.

According to yet another embodiment of the disclosure, two or moreinstances performing the same function may be running in one physicalhardware device. When two or more instances performing the same functionare running in one physical hardware device, a target, e.g., userequipment (UE), to be controlled and/or serviced by each instance may bedifferent. If one instance performs a specific operation for providingcontrol and/or service to the same target, e.g., one UE, the one UE mayhave different identifiers for different services and/or controls.

In the following description, one NF will be described as one device forconvenience of description. However, as described above, each of the NFsmay be implemented as one or two or more instances, and all of thesecases may be included. Also, other NFs not described above will bedescribed as devices according to the above description. However, inactual implementation, each NF may be implemented as one or two or moreinstances.

FIG. 2 is a diagram illustrating a structure of API-based connectionamong a user equipment, a mobile communication network, and an edgecomputing system according to an embodiment of the disclosure.

Referring to FIG. 2 , the UE 50, the 3GPP core network 40 as an exampleof the mobile communication network, and the first edge data network areillustrated.

The UE 50 may correspond to the electronic device described above inFIG. 1 . In the illustrated case, the UE contains therein the mobileterminal 51, the edge enabler client 52, and the plurality ofapplications 53, 54, and 55. The plurality of applications 53, 54, and55 may be different edge service application. For example, the firstapplication 53 may be an application for providing an edge computingservice to the user by receiving a first edge computing service, thesecond application 54 may be an application for providing an edgecomputing service to the user by receiving a second edge computingservice, and the third application 55 may be an application forproviding an edge computing service to the user by receiving a thirdedge computing service.

Each of the applications 53, 54, and 55 may be provided with the edgecomputing service through the edge enabler client 52. In addition, eachof the applications 53, 54, and 55 may be provided with the edgecomputing service from the edge data network by accessing a mobilecommunication network, for example, a base station of a 3PP networkincluding the 3GPP core network 40, through the mobile terminal 51.

Although not illustrated in FIG. 2 for a radio access network (RAN)including a base station, it may be understood based on the scheme ofFIG. 1 . Also, the 3GPP network is illustrated as an example of themobile communication network. According to an embodiment of thedisclosure, the 3GPP core network 40 can provide an application programinterface (API) set 41 composed of APIs that can be used by theapplication function (AF). The edge enabler server 100 or the edgeapplication servers 101, 102, and 103, which can use (utilize) the AFs,can interact with the 3GPP network by using one or more specific APIs inthe API set 41 provided by the 3GPP network.

In addition to the above description, the edge configuration server 30may transmit/receive (via a scheme of request/response,subscription/notification, or the like) information necessary for theedge computing service to/from the 3GPP network through the API in theAPI set 41 provided by the 3GPP core network 40. Also, as above, theedge enabler server 100 may interact with the 3GPP network by using theAPI in the API set 41 provided by the 3GPP core network 40. Throughthis, even in case where an edge application server provider does nothave a service level agreement with a 3GPP network operator, the edgeenabler server 100 can provide an API set to the registered edgeapplication servers 101, 102, and 103. In this case, the API set 110provided by the edge enabler server 100 to the edge application servers101, 102, and 103 may use the API set 41 received from the 3GPP corenetwork 40 as it is. In another example, the API set 110 provided by theedge enabler server 100 to the edge application servers 101, 102, and103 may be provided after processing the API set 41 received from the3GPP core network 40 in the form of being recognizable in the edgeapplication servers 101, 102, and 103. In still another example, theedge enabler server 100 may provide the edge application servers 101,102, and 103 with only usable (utilizable) APIs in the API set 41received from the 3GPP core network 40. Accordingly, the edgeapplication servers 101, 102, and 103 can indirectly interact with the3GPP core network 40 through the edge enabler server 100 in which theyare registered. Alternatively, in some cases, the edge applicationservers 101, 102, and 103 may directly interact with the 3GPP corenetwork 40 by using (utilizing) the API provided by the edge enablerserver 100 in which they are registered.

On the other hand, even when the edge application server provider has aservice level agreement with the 3GPP network operator so that the edgeapplication servers 101, 102, and 103 can directly use the API set 41provided by the 3GPP network, it may be configured to indirectlyinteract with the 3GPP network through the edge enabler server 100 forefficient API use.

First Embodiment

Hereinafter, operations of transferring edge application informationbetween the edge data network and the 3GPP network according to thefirst embodiment of the disclosure will be described.

FIG. 3 is a diagram illustrating a signal flow for transferring edgeapplication information required for AF request creation andtransmission according to an embodiment of the disclosure.

At step 301 (step 1), the edge application server (EAS) 101 may transmita registration request message to an edge enabler server (EES) 100 inwhich the EAS can be registered. An example of the EES 100 in which theEAS 101 can be registered will be described with reference to FIG. 1 .In case of the first EAS 101 and the second EAS 102 running in the edgehosting environment of the EES 100, the EES 100 becomes an EES in whichboth EASs can be registered. In case of the first EAS 201 running in theedge hosting environment of the EES 200, the EES 200 becomes an EES inwhich the EAS can be registered. In the following embodiment, it isassumed that the first EAS 101 running in the edge hosting environmentof the EES 100 transmits a registration request message.

An operation of transmitting the registration request message will bedescribed as an example. The EES 100 may acquire the followinginformation from the EAS 101 through an edge application serverregistration procedure. The information that the EES 100 can acquire atthe time of transmitting the edge application server registrationrequest message may be at least one of EAS service continuitycapability/support, AF request support, traffic routing requirementinformation, EAS data network access identifier (DNAI) information, andAF transaction identifier. When the edge application server registrationrequest message includes the AF transaction identifier, information(e.g., subscription correlation ID, notification target ID, etc.)related to a subscription performed through an AF transaction that canbe identified through the AF transaction identifier may be included inthe edge application server registration request message. In anotherexample, the above information may be transferred from the EAS 101 tothe EES 100 through a separate procedure other than the edge applicationprocedure.

The above-mentioned information acquired when the edge applicationserver registration request message is transmitted will be described inmore detail.

The EAS service continuity capability/support information provided bythe EAS 101 may include at least one of stateful/stateless typeinformation of a service, whether there is a capability of performingapplication context transmission, and whether it is necessary to ensurethe preservation of a UE IP address. The stateful/stateless service typemay be information indicating whether there exists a continuousoperation or service state between a client (e.g., the EEC 52 of the UE50) and a server (e.g., the EAS) and whether the service is a type ofrequiring the corresponding state information in order for the client toreceive continuously the service. For example, when the service type is“stateful”, a continuous operation or service state may exist betweenthe EEC 52 and the EAS, and the EEC 52 may be in a state of desiring acontinuous service. Conversely, when the service type is “stateless”,there may be no continuous operation or service, or even if the serviceexists, it may be in a state of desiring no continuous service.

Such information included in the edge application server registrationrequest message may be mapped to an application relocation possibilityand a UE IP preservation indication by the EES 100 or may be referred towhen generating an AF request message by generating the correspondinginformation.

Here, when generating the AF request message, a case where the EASservice continuity capability/support information indicates that the EASprovided service is stateful and that the EAS can perform applicationcontext transfer to another EAS may be interpreted as follows. The EES100 may indicate the application relocation possibility in the AFrequest. Here, this indication of the application relocation possibilityin the AF request may be an indicator that instructs a specific networkfunction device of the mobile communication network, e.g., the 3GPPnetwork, involved in session management of the UE to wait foracknowledgement or notification regarding the completion of theapplication context relocation from the EES 100 before configuration andactivation of a user plane path.

Next, the AF request support information may include information aboutwhether the EAS 101 can directly transmit the AF request message to the3GPP network device (network exposure function, policy and chargingfunction, session management function, access mobility function, etc.),and information about whether it will directly transmit the AF requestmessage (responsibility for AF request). In an example, the EAS 101 candirectly transmit the AF request message, but if desiring to delegatethe AF request message to the EES 100, the corresponding indication maybe included in the AF request support information.

Specifically, if the AF request support information indicates that theEAS 101 cannot directly transmit the AF request message or indicatesthat the responsibility/operation for the AF request message isdelegated to the EES 100, the EAS 101 may transmit the AF requestmessage to the mobile communication network through the EES 100, wheninteractions are required, without directly interacting with the 3GPPnetwork. To this end, after the EAS 101 performs the EAS registrationoperation, the EES 100 may transmit the AF request message for thecorresponding EAS 101 to the 3GPP network.

Next, the traffic routing requirement information may include all kindsof information (e.g., routing profile ID, N6 routing information, etc.)required to route the application data traffic of the UE to the edgeapplication through the N6 interface. If the purpose of AF influence isN6 traffic routing, corresponding information should be included. Inaddition, it is possible to configure and transfer traffic routingrequirement information for each DNAI.

If the traffic routing requirement information is provided from the EAS101, the EES 100 should insert the traffic routing information aboutinterface-related information (e.g. DNAI), etc. for access to thecorresponding EAS or EAS in the AF request message when transmitting theAF request message having the purpose of establishing traffic routing.

Next, the EAS DNAI information may contain DNAI information of the datanetwork required for the EAS 101 access when the EAS 101 is accessiblethrough a mobile communication network, e.g., 5G core (5GC). A pluralityof DNAIs may be used for one EAS access. The DNAI information may beused to specify a UPF that supports the corresponding DNAI (a pluralityof UPFs may correspond to one DNAI).

When the EES 100 is provided with the EAS DNAI (The EES 100 may acquireDNAI information from the EAS 101 in various methods. For example, itmay be in local configuration by receiving network configurationinformation (e.g., UPF-related information) of an operator or acquiredfrom a node (e.g., an orchestrator and management node) in charge of EASinstallation (instantiation)), the EES 100 may collect the EAS DNAIinformation providing the same service and include/map it in/topotential application location information. In addition, the providedDNAI may be mapped to an AF-service identifier by the EES 100 andincluded in the AF request message transmitted to the network exposurefunction (NEF) device.

Also, in case of acquiring the DNAI information of the EASs, the EES 100may receive UE's accessible DNAI information (target DNAI) according toa user plane path change of the UE from the 3GPP network, map it to theDNAI for each EAS, and select a new EAS according to the movement of theUE.

The above-described operation of the EES 100 for mapping the EAS DNAIinformation and the EAS service area and potential application locationinformation may also be performed by the edge configuration server 30.Further, the edge configuration server (ECS) 30 may perform mappingbetween the EES DNAI information and the EES service area (or the EDNservice area). For example, when the EES DNAI information is given, theECS 30 may define/infer/map the EES service area based on the servicearea of the UPF connected to the EES DNAI, and also define/infer/map theedge computing service area based on the DNAI information of all theEESs connected to the ECS 30. Operations of the ECS 30 based on the EESDNAI information or the EES service area will be described below withreference to FIGS. 7 to 9 .

The AF transaction identifier (ID) may include specific informationrelated to the AF request message having been performed for directinteractions between the EAS 101 and the 3GPP network. Using the AFtransaction ID information, information on the previously performed AFrequest can be obtained. For example, if the purpose of the AF requestis to receive a notification for a specific event from the 3GPP networkdevice, subscription information for the notification can be checkedthrough the AF transaction ID. For example, it is possible to checkwhether a subscription to a user plane (UP) path change eventnotification or UE location reporting for a specific UE has beenperformed, or check related information (subscription correlation ID,notification target ID, notification correlation ID, etc.).

At step 302 (step 2), the EES 100 may check EAS registrationauthorization, and at step 303 (step 3), the EES 100 may transmit an EASregistration response message to the EAS 101. In this case, the EES 100may store the information provided by the EAS 101 in an internal memory(not shown) and transmit the EAS registration response message.

Through steps 301 to 303, the EAS registration procedure may becompleted. After the completion of the EAS registration procedure, theEES 100 may create at step 304 (step 4) an AF request message by usingthe EAS information stored in the previous procedure, and transmit thecreated AF request message to a mobile communication network, e.g., the3GPP network 300 at step 305 (step 5). Here, the 3GPP network 300 mayrefer to all of the base stations 111, 112, 113, 114, 211, and 212 shownin FIG. 1 and the 3GPP core network 40 shown in FIG. 2 . In case wherethe disclosure is actually applied, the 3GPP network 300 may be aspecific network function (NF) device capable of communicating with theedge data network when the 3GPP core network 40 is implemented as 5GC.On the other hand, when the 3GPP core network 40 is implemented as 4GC,the 3GPP network 300 may be a specific network node capable ofcommunicating with the edge data network.

A time point when the EES 100 transmits the AF request message as instep 305 may be the following two cases. First, the AF request for theservice provided by the EAS 101 may be transmitted to the 3GPP network300 immediately after the EAS registration. Second, the AF request maybe transmitted to the 3GPP network 300 after an EAS discovery requestmessage for the EAS 101 is received.

In any one of the above two cases, the EES 100 may transmit the AFrequest message to the 3GPP network 300 by using information in an EASprofile stored in the EES 100.

In case of creating the AF request message, information on potentiallocations of applications may be generated by collecting DNAIinformation of EASs providing the same service among EASs registered inthe EES 100. The information on potential locations of applications maybe included in the AF request message and transmitted to the 3GPPnetwork 300. In this case, the 3GPP network 300 may be, for example, oneof NEF (not shown), SMF (not shown), PCF (not shown), and UDR (notshown).

In addition, when creating the AF request message, the EES 100 mayconfigure a spatial validity condition and a temporary validitycondition in the AF request message, based on the EAS service area andEAS schedule information. In particular, in case where a plurality ofEASs providing the same service exist and are registered in the EES 100,such validity conditions may be configured by aggregating the servicearea and schedule information of the EASs. If there is a geographic zoneidentifier that is configured between the EES 100 and the 3GPP network300, the spatial validity condition may be configured in the AF requestmessage by mapping the EAS service area information to the geographiczone identifier. In another example, the EES 100 may infer a geographicservice area based on the obtained EAS DNAI information or map a DNAIvalue to the geographic zone identifier and then configure it as thespatial validity condition.

In addition, the EES 100 may map the EAS service area and the DNAI,based on the EAS service area information and the network installationinformation of the 3GPP network 300. If the EAS 100 does not provideDNAI information, the EES 100 may map the EAS service area informationto the DNAI, and define a potential application location by collectingthe mapped DNAIs. When a specific DNAI is given, for example, when anEAS request for a specific DNAI is received from the 3GPP network 300,the EES 100 may identify (check), based on the potential applicationlocation (EAS DNAI list) defined as described above, whether the EAScorresponding to the specific DNAI has been registered in the EES 100.

The EAS service continuity support information provided by the EAS 101includes information on whether application context transfer/relocationcan be performed. If it is configured to be performed, the EES 100 maymap corresponding information to the application relocation possibilityinformation when creating/transmitting the AF request message.

In the embodiment described above, a time point when the EES 100transmits the AF request message may be one of the following timepoints.

First, after the EAS registration procedure is completed, an AF requestmessage may be transmitted in advance to UEs to access the EAS 100. TheAF request message may be transmitted in advance for determining routingfor traffic provided to all UEs accessing EAS DNAI acquired through theEAS registration procedure or other routes. That is, before theconnection between the edge application client (EEC) 52 in the UE 50 andthe EAS 101 is established, the AF request message may be transmitted inadvance.

Second, the AF request message may be transmitted after the EASregistration procedure, after the EES 100 receives an EEC registrationrequest message or an EAS discovery request message from the UE 50, andafter detecting that application data traffic between the UE 50 and theEAS 101 will occur.

Third, after the EAS registration, EEC registration, and EAS discoveryprocedures are completed, and after a PDU session in which applicationdata traffic can be exchanged between the UE 50 and the EAS 101 isestablished, the AF request message may be transmitted for theestablished session.

Second Embodiment

Hereinafter, procedures for a user plane path management between an edgecomputing network and a mobile communication network according to asecond embodiment of the disclosure will be described.

FIG. 4 is a diagram illustrating a signal flow for a user plane (UP)path management event notification according to an embodiment of thedisclosure.

In the description of FIG. 4 , it is assumed that nodes of the edge datanetwork are the EAS 101 and the EES 100 in FIG. 1 described above, andthe 3GPP network 300 may be at least one node included in the 3GPP corenetwork in FIG. 2 .

At step 401 (step 1), the EAS 101 transmits a user plane (UP) pathmanagement event application program interface (API) subscribe requestmessage to the EES 100. This message may include at least one of asubscription type (preference or indication), AF ACK preference, AFtransaction identifier, and EAS DNAI information.

The EAS 101 may transmit a subscribe type or notification type relatedconfiguration (early notification and/or late notification) included inthe subscription type. By transmitting the subscribe type ornotification type related configuration, the EAS 101 enables the EES 100to configure a subscribe type for the UP path management eventnotification of the 3GPP network 300. For example, the EAS 101 mayreceive a notification in advance before a new UPF configuration isperformed (immediately after UP path change detection) according to themobility of the UE providing the service, and then advance a time pointof starting to perform a subsequent operation, for example, applicationcontext relocation, as follows. The early notification may be configuredas the subscribe type or notification type and included in the UP pathmanagement event API subscribe request message. In another example, incase of desiring to receive a notification just before activation afterUPF configuration, the late notification may be configured as the typeand included in the request message. Case of desiring to receive boththe early notification and the late notification is also possible.

A configuration for the subscription/notification type as describedabove may be directly determined by the EES 100 itself without receivinga message about the type from the EAS 101.

For example, based on the EAS information acquired through the EASregistration procedure (e.g., FIG. 3 described above), the EES 100 mayconfigure the notification type to early or late depending on the timerequired for the EAS 101 to perform application context transfer or onthe application context size, and include it in the AF request message.For example, if the size of the application context to be transferred(relocation) by the EAS 100 is large, the AF request message may beconfigured as the early notification and transmitted.

The EAS 101 may enable the SMF (not shown) in the 3GPP network 300 towait for the acknowledgment of the AF before performing the UPFconfiguration or UPF activation according to the UP path change. Forthis, the AF ACK preference (or indication of EAS acknowledgment) may beconfigured and included in the UP path management event API requestmessage to be transmitted to the EES 100. Upon receiving thecorresponding indication, the EES 100 may be configured to include anindication of “AF acknowledgment to be expected” when performing asubscription for the UP path management event notification for the 3GPPnetwork 300. In addition, when the UP path change event occurs, the AFacknowledgment may be transmitted to the SMF after it is recognized thatthe EAS 101 has completed the app context relocation/transfer operation.In case where the indication of EAS acknowledgment is configured, adetailed subsequent operation is illustrated in FIG. 5 to be describedbelow, and thus a detailed description thereof will be omitted.

Even if the EAS 101 does not provide the above AF ACK preference orindication of EAS acknowledgment, the EES 100 may configure thecorresponding parameter by itself with reference to EAS profileinformation. For example, the subscription/notification type may beconfigured based on EAS service continuity support, EAS service type, orEAS service key performance indicator (KPI) included in latency-relatedinformation.

If the EAS 101 has performed a subscription for the previous UP pathmanagement event notification or the EAS 101 has related information,the EAS 101 may provide the subscription parameter such as AFtransaction identifier or subscription correlation ID/notificationcorrelation ID for the related past operation to the EES 100. Uponreceiving such information, when the EES 100 generates an AF requestmessage, the EES 100 may be configured by including AF subscriptioninformation (information on AF subscription to corresponding SMF events)in the AF Request message based on the information on thesubscription-related parameter provided by the EAS 101.

Through the above operation, when the EES 100 receive the UP pathmanagement event API subscribe request message, the EES 100 may check aUP path management event between a specific node of the 3GPP network 300and the requested UE, at step 402 (step 2). That is, based on theinformation at the above-described step 401, the EES 100 may perform aprocedure for receiving a notification about the occurrence of a UP pathmanagement event with a specific node of the 3GPP network.

Through the step 402, the EES 100 may check whether to subscribe to theUP path management event, and if necessary, the EES 100 may subscribe tothe UP path management event to the 3GPP network device. At step 403(step 3), the EES 100 may generate a user plane path management eventAPI subscribe/unsubscribe response message and transmit it to thecorresponding EAS 101.

Third Embodiment

Hereinafter, a procedure for UP path management event notification whenAF acknowledgment preference is configured according to a thirdembodiment of the disclosure will be described.

FIG. 5 is a diagram illustrating a signal flow for providing a userplane path management event notification message when AF acknowledgmentpreference is configured according to an embodiment of the disclosure.

In describing FIG. 5 , it is assumed that among nodes of the edge datanetwork, the EAS 101 and the EES 100 of FIG. 1 are source nodes, and theEAS 201 and the EES 200 of FIG. 1 are target nodes. In addition, it isassumed that the 3GPP network 300 is implemented with the 5GC 40.

At step 501 (step 1), the source-EAS (S-EAS) 101 may include anindication of EAS acknowledgment or AF acknowledgment in the UP pathmanagement event API subscribe request message and provide it to thesource-EES (S-EES) 100. In this case, at step 502 (step 2), the S-EES100 may include an indication of “AF acknowledgment to be expected” inthe AF request message and transmit a subscribe operation for the UPpath management event notification to the 3GPP network, that is, aspecific network function (NF) device (e.g., NEF, PCF, or SMF) of the5GC 40.

Upon the receiving the message in step 502, when a UP path change eventoccurs, that is, at step 503 (step 3), the 5GC 40 may provide a relatednotification to the S-EES 100 and/or the S-EAS 101. If the indication of“AF acknowledgment to be expected” is included at the step 502, the 5GC40 sends a notification about the UP path change event to the S-EES 100and waits for the reception of the AF acknowledgment message withoutimmediately performing UPF configuration and activation according to theUP path change. If the above indication is not included, the 5GC device(e.g., SMF) may immediately perform the UPF configuration and activation(configuration is possible based on N6 routing information provided fromthe AF request message). The 5GC device (e.g., SMF) may also receive theN6 routing information from the T-EES 200 or the T-EAS 201. The S-EES100 which received the UP path change event message from the 3GPPnetwork, may start an application context relocation procedure at step504 (step 4).

At step 505, the S-EES 100 may perform a procedure for receiving,through other EAS and other EES, the user plane data to be provided tothe UE through the ECS 30 according to the movement of the UE or thechange of the UPF. For example, the S-EES 100 may inquire of the ECS 30about a target EAS capable of providing the user plane data to the UEand an EES including the target EAS, and receive related information.Therefore, the S-EES 100 may determine the T-EES 200 and/or the T-EAS201 based on the information acquired from the ECS 30. The T-EES 200 orT-EAS 201 determined at the step 505 may provide N6 routing informationfor DNAI connected to the T-EAS 201 to the S-EES 100 (e.g., the S-EES100 may request and receive the corresponding information from the T-EES200). The S-EES 100 may perform step 509 below based on the N6 routinginformation for the T-EAS 201 received from the T-EAS 201 or the T-EES200, or perform AF request to influence traffic routing through aseparate operation.

Thereafter, at step 506 (step 6), the S-EES 100 may transmit anapplication context transfer request message to the S-EAS 101. At step507 (step 7), the S-EAS 101 may transfer the application context to theT-EAS 201 directly or through the S-EES 100.

After performing the above-described steps 504 to 507, the S-EAS 101 maytransmit an EAS acknowledgment message (or via the application contexttransfer response message) to the S-EES (100) at step 508 (step 8) inorder to inform that the UPF configuration or activation according tothe UP path change may be performed.

At step 509 (step 9), the S-EES 100 that has received the correspondingacknowledgment message may transmit an AF acknowledgment message to aspecific network function of the 3GPP network 40, for example, NEFand/or SMF, in order to inform that UPF configuration/activation ispossible.

At step 510 (step 10), the specific node, e.g., SMF, of the 3GPP networkthat has received the AF acknowledgment message from the S-EES 100 mayperform the UPF configuration/activation. That is,configuration/activation of UPF for transmitting the user plane databetween the UE 50 and the T-EAS 201 may be performed. In this regard,referring to FIG. 1 , the operation of the 3GPP network may be asfollows. First, it is assumed that the edge computing service isprovided to the UE 50 through the second UPF 122. When the SMF receivesthe AF acknowledgment message directly from the S-EES 100 or throughanother NF of the 3GPP, the SMF may determine the UPF 221 to receivedata from the T-EAS 201 through the T-EES 200 or directly from the T-EAS201. Therefore, the UPF2 122 of the first edge data network 10 may stopthe transmission of user plane data to the UE 50, and the UPF1 221 ofthe second edge data network 20 may be activated to transmit user planedata to the UE 50.

FIG. 6 is a diagram illustrating a signal flow for providing a userplane path management event notification message when AF acknowledgmentpreference is configured according to an embodiment of the disclosure.

In describing FIG. 6 , it is assumed as in FIG. 5 that among nodes ofthe edge data network, the EAS 101 and the EES 100 of FIG. 1 are sourcenodes, and the EAS 201 and the EES 200 of FIG. 1 are target nodes. Inaddition, it is assumed that the 3GPP network 300 is implemented withthe 5GC 40.

In addition, when FIG. 6 is compared with FIG. 5 , steps 501 to 508 maybe the same operations as steps 601 to 608 of FIG. 6 . Hereinafter, adifference between FIG. 5 and FIG. 6 will be described.

First, the operation of the S-EAS 101 that transmits the applicationcontext transfer response message to the S-EES 100 at step 608 may bethe same as that of FIG. 5 described above. In FIG. 6 , the S-EES 100may transmit an S-EAS response message for a UP path change notificationto the T-EES 200 in response to the application context transferresponse message received from the S-EAS 101. That is, the S-EES 100 mayreceive an acknowledgment message from the S-EAS 101 and then transferit to the T-EES 200. Upon receiving the acknowledgment of the S-EAS 101,the T-EES 200 may send an AF acknowledgment message to the SMF of the5GC 40 at step 609 (step 9) instead of the S-EAS 101 or the S-EES 100(in case where the UE 50 has performed EEC registration to the T-EES 200or is out of the spatial validity condition of the AF request messageissued by the S-EES 100). The SMF of the 5GC 40 that has received thismay perform UPF configuration/activation at step 610 (step 10). Here,the operation of the SMF performing the UPF configuration/activation maybe the same operation as described with reference to FIG. 5 . Therefore,the redundant description thereof will be omitted.

FIG. 7 is a diagram illustrating a signal flow for a T-EAS discoveryoperation based on DNAI of EES according to an embodiment of thedisclosure.

In describing FIG. 7 , it is assumed that among nodes of the edge datanetwork, the EAS 101 and the EES 100 of FIG. 1 are source nodes, and theEES 200 of FIG. 1 is a target node. In addition, it is assumed that the3GPP network 300 is implemented with the 5GC 40. It is also assumed thatthe following operations have been performed before the signal flowshown in FIG. 7 .

First, as previously described in the embodiments of FIGS. 3 to 6 , theEES 100 has known DNAI information (e.g., EAS DNAI) used to access theEAS 101 or the edge data network in which the EAS 101 is installed. TheEAS DNAI information may be locally configured in the EES 100, provideddirectly from the EAS 101, or provided from an orchestrator & managementsystem node (not shown).

Second, the EES 100 is in a state that it has created the AF requestmessage instead of the EAS 101 and has performed the subscription to theUP path management event notification message to the 3GPP network 40. Inaddition, the AF request message created/transmitted by the EES 100 mayinclude DNAI information connected to the EAS 101 or the EES 100 (EASDNAI information may be designated as a potential location ofapplication).

At step 700 (step 0), the source EES (S-EES) 100 may receive a userplane (UP) path change notification message from the 3GPP network (e.g.,5G core network) 40. In this case, the UP path change notificationmessage may include a target DNAI value used by the UE 50 to access thedata network through a new UP path. The source EES 100 may transfer(forward) the above notification message to the source EAS 101.

At step 701 (step 1), the source EAS 101 may receive the target DNAIvalue through the UP path change notification message from the sourceEES 100, and check (identify) whether the target DNAI is a DNAIaccessible to the source EAS itself. If the target DNAI does not providea connection with the source EAS (e.g., in case of a DNAI connected to aUPF that is not included in the EAS service area), or if it is a UP paththat causes an additional delay even if connection is possible, an EASdiscovery request message for selecting a new EAS (target EAS) may betransmitted to the source EES 100. Therefore, the source EAS 101 mayconfigure a discovery reason of the EAS discovery request message to aUP path change and include the target DNAI in the EAS discovery requestmessage.

At step 702 (step 2), the source EES 100 may compare the target DNAIincluded in the EAS discovery request message with the DNAI values ofthe EAS registered or stored therein and, based on this, determinewhether to interact with the edge configuration server 30.

First, if there is an EAS DNAI value that matches the target DNAI, andif the EAS connected to the DNAI can provide the same service as thesource EAS, the source EES 100 may transfer the target EAS informationregistered therein to the source EAS 101 without a need to interact withthe edge configuration server 30 to discover the target EES. In thiscase, it may be configured to perform step 705 (step 5) withoutperforming steps 703 to 704 illustrated in FIG. 7 .

Second, if there is no EAS DNAI value that matches the target DNAI, thesource EES 100 may perform interactions with the ECS 30. The second casemay be further classified as follows.

(1) In order to interact with the ECS 30, the target DNAI provided fromthe 3GPP network 40 may be transmitted to the ECS 30. In response, theECS 30 may select the target EES based on the target DNAI. If the EESdoes not provide the target DNAI and only provides UE information orsource EAS information (e.g., EAS ID, type, endpoint address, etc.)connected to the UE, the ECS 30 may interact with the 3GPP network 40and acquire the location of the UE or the DNAI value. The ECS 30 mayprovide target EES information (such as ID and address information)selected based on the target DNAI to the source EES 100. In FIG. 7 , thetarget EES will be described as the EES 200 described in FIG. 1 . Assuch, the EES 100 that has received the target EES information providedby the ECS 30 can perform the target EES interaction step 703 b (step 3b).

(2) In case of failing to acquire information on the target EES throughinteractions with the ECS 30, the ECS 30 may check whether there is atarget EES connectable based on the target DNAI received from the sourceEES 100. In case of failing to discover a target EES or target EASconnectable through the target DNAI (in case that the target DNAI valueis connected to a data network that does not provide access to the edgecomputing server (EAS or EES)), it may be determined that the edgecomputing service is not supported in the current region (the movedregion) of the UE 50. Therefore, the UE needs to receive a service fromthe central server, and for this, step 703 a (step 3 a) may beperformed.

The step 703 a (step 3 a) will be described. This is the case where thesource EES 100 fails to discover the edge computing server (EES or EAS)accessible through the target DNAI as a result of interactions with theECS 30. Therefore, the UE 50 should perform an operation for accessingthe central server without finding a new EAS. For this, a notificationmessage may be transmitted to the UE 50. This notification message mayindicate a target EAS discovery failure or an edge computing serviceunavailability.

[A]. In case of the target EAS discovery failure, there may exist a caseof performing continuous access to the existing source EAS. That is,this may be a case of continuing communication with the existing sourceEAS 101 and the source EES 100.

[B]. In case of the target EAS discovery failure, a case of performingaccess to the central server is also possible. In this case, (1) thecorresponding EAS information (related information such as EAS addressand EAS type) and lifetime stored in a cache and DNS cache in the EEC 52of the UE may be initialized/deleted and DNS query is performed. (2) Theabove notification message may be transmitted to the source EAS 101, andthe source EAS 101 may perform application context transmission to thecentral server (not shown).

The step 703 b (step 3 b) will be described. The source EES 100 maytransmit an EAS discovery request message to the target EES 200 obtainedas a result of interactions with the ECS 30. In this case, the sourceEES 100 may transmit the target DNAI by including it in the EASdiscovery request message. The EAS discovery request message may includeinformation related to the source EAS 101 (ID and address information)and information related to the UE having received a service from thesource EAS 101. In order to obtain UE identifier and UE-relatedinformation, the UE-related information may include information (3GPPnetwork function ID, address, AF transaction ID, subscriptioncorrelation ID, notification correlation ID, notification targetaddress, notification event ID, etc.) on interactions (AF request or AFtransaction) between the source EES 100 and the 3GPP network.

At step 704 (step 4), the target EES 200 may select the target EAS basedon the target DNAI value and the source EAS-related information providedfrom the source EES 100, and transmit the target EAS information (ID andaddress information, etc.) to the source EES 100.

At step 705 (step 5), the source EES 100 may provide the target EASinformation, provided from the target EES 200, to the source EAS 101(step 705 a) and the UE 50 (step 705 b). The operation performed at step705 may include one of the following operations.

First, the edge enabler client 52 in the UE 50 may store the receivedtarget EAS information, break the binding between the existingapplication client and the source EAS information, and bind and storethe application client and new target EAS information. Information onthe source EAS 101 may be deleted from the cache of the EEC 52(thereafter, an EAS discovery request message or a DNS query for thecorresponding application client is processed based on the target EASinformation).

Second, the source EAS 101 may redirect application data traffic to thetarget EAS based on the target EAS information provided from the sourceEES 100. The application context stored in the source EAS 101 may betransmitted to the target EAS (e.g., the EAS 201 in FIG. 1 ). If theapplication context is not stored in the source EAS 101, the target EASmay perform an operation to receive the application context from a nodethat stores the corresponding context.

Third, in case where the source EES 100 cannot provide the target EASinformation to the UE 50 (e.g., in case where the UE 50 moves to aregion inaccessible to the source EES 100 or a region inaccessible tothe source edge data network (EDN) containing the source EES 100), thetarget EES 200 may transmit the target EAS information to the UE 50. Inanother example, the source EAS 101 that has received the target EASinformation from the source EES 100 may notify such information to theUE 50 (the source EAS 101 may transmit the target EAS information to theapplication client, which may provide that information to the edgeenabler client).

FIG. 8 is a diagram illustrating a signal flow for an operation ofDNAI-based target EAS discovery of EES according to an embodiment of thedisclosure.

The operation of FIG. 8 may be a simplified procedure corresponding to aprocedure of performing the above-described operation of step 703 a(step 3 a) in FIG. 7 . Therefore, step 800 (step 0) may be the sameoperation as the above-described operation of FIG. 7 .

In response to the operation of step 800, the source EES 100 maydetermine that the target DNAI provided from the 3GPP network 40 is aDNAI that cannot provide the edge computing service by itself. In thiscase, the source EES 100 may immediately transmit at step 801 (step 1) anotification message indicating the edge computing serviceunavailability to the EEC 52 of the UE 50. Therefore, the EEC 52 of theUE 52 may recognize that it needs to access the central server. That is,through the step 801, the source EES 100 may induce the EEC 52 of the UE50 to access the central server.

If the UE 50 moves to an area in which communication with the source EES100 is impossible, the source EES 100 may notify this fact to the edgeconfiguration server 30. In this case, the ECS 30 may induce access tothe central server by transferring a notification message indicating theedge computing service unavailability to the UE 50. In another method,the edge configuration server 30 may subscribe to the 3GPP network 40 inadvance to receive a notification message when an event that the UE 50moves to an unserviceable area occurs. In this case, upon receiving sucha notification message from the 3GPP network 40, the ECS 30 may notifythis the EEC 52 of the UE 50. Accordingly, step 802 (step 2) can beinduced. In still another example, the ECS 30 may precede a subscribeoperation to the 3GPP network 40 to receive a notification message forthe UP path change message of the UE 50. As such, in case of firstperforming the subscribe operation to receive the notification messagefor UP path change message, the ECS 30 may determine (identify) whetherthe edge computing service is available, based on target DNAIinformation in the UP path change notification message.

Then, according to the disclosure, a method for the source EES 100 orthe edge configuration server 30 to determine that the edge computingservice cannot be provided to the UE 50 will be described.

First, a specific node of the 3GPP network 40, for example, the SMF orNEF may inform in advance the source EES 100 or the edge configurationserver 30 about a target DNAI value that cannot provide the edgecomputing service. For example, the operator may recognize in advanceavailable/unavailable DNAI values to provide the edge computing service,based on a contract with the edge computing service provider and networkconfiguration information acquired in advance. Accordingly, the operatorcan preconfigure a DNAI set composed of the available/unavailable DNAIvalues for providing the edge computing service. The preconfigured DNAIset may be defined for each application service and mapped to at leastone value among EAS ID, EAS type, application ID, and AC type, which aresupported by the DNAI set. In another method, the DNAI set capable ofusing a service provided by a specific edge computing service providermay be predefined for each edge computing service provider (ECSP).Accordingly, the predefined DNAI set may be mapped to the ECSP ID. Instill another method, the DNAI set may be predefined for all the edgecomputing services. The DNAI set defined in this method may be locallyconfigured in the edge configuration server (ECS) 30 or each EES, or maybe stored in SMF, PCF, UDM, UDR, etc. of the 3GPP network. For example,the SMF may determine (identify) the availability of the edge computingservice, based on the DNAI value newly determined according to themovement of the UE and the service information (EAS ID, application ID,EAS type, etc.) being provided to the UE.

Second, the DNAI value of edge computing service unavailability may belocally configured in the source EES 100 or the edge configurationserver 30 (e.g., in case of being determined and configured by thenetwork operator), or information obtained by previously performing thetarget EAS discovery operation for other UE may be stored.

In case of receiving the corresponding notification message, the UE 50may perform initializing/deleting the corresponding EAS information(related information such as EAS address and EAS type) and lifetimestored in the EEC cache and DNS cache and perform a DNS query operation.

The source EES 100 may transmit the above notification message to thesource EAS 101 as well, and the source EAS 101 receiving thenotification message may perform an operation of transmitting theapplication context to the central server.

FIG. 9 is a diagram illustrating a signal flow for a DNAI-basedapplication context relocation procedure according to an embodiment ofthe disclosure.

In FIG. 9 , an application context relocation procedure when selectingthe target DNAI-based target EES and target EAS described above will bedescribed. In describing FIG. 9 , it is assumed that the EAS 101 and theEES 100 of FIG. 1 are source nodes, and the EAS 201 and the EES 200 ofFIG. 1 are target nodes. In addition, it is assumed that the 3GPPnetwork 300 is implemented with the 5GC 40.

At step 900, the source EES 100 may receive a UP path changenotification message from the 3GPP network 40. Here, the UP path changenotification message may include, as described above in the embodimentsof FIGS. 7 and 8 , may include the target DNAI and theavailability/unavailability of edge computing service through the targetDNAI.

At step 901 (step 1), the source EES 100 may determine whether tointeract with the edge configuration server 30, based on informationincluded in the UP path change notification message received at the step900. When interactions with the ECS 30 is determined, the source EES 100may transmit a target DNAI to the ECS 30 at step 902 (step 2). Inaddition, the ECS 30 may determine a target EES that can be accessedthrough the target DNAI provided at the step 902, and providecorresponding information, that is, the determined target EESinformation, to the source EES 100.

After performing the step 902, the source EES 100 may transmit, at step903 (step 3), a context relocation request message including the targetDNAI and the source EAS information to the target EES 200 through targetEES address information provided from the ECS 30.

The target EES 200 receiving the context relocation request message atthe step 903 may select the target EAS 201, based on information (targetDNAI and source EAS information) in the message received from the sourceEES 100. In addition, at step 904 or in succession to the step 904, thetarget EES 200 may perform an additional operation of driving the targetEAS 201 if necessary. After the availability of the target EAS 201 ischecked, the target EES 200 may transmit a context relocation responsemessage (including target EAS information) to the source EES 100 at step905 (step 5). At step 905, the source EES 100 may transmit anapplication context transfer request message to the source EAS 101 inresponse to receiving the context relocation response message. Then, atstep 907 (step 7), the source EAS 101 may transfer the application (app)context in response to receiving the application context transferrequest message.

At step 908 after performing the step 907, the source EAS 101 maytransfer, to the source EES 100, the fact that the application contexttransfer is completed. Accordingly, the S-EES 100 receiving from theS-EAS the fact that the context transfer has been completed may beconfigured to send an AF acknowledgment message in previous interactionswith the 3GPP network 40. This may be a case that in FIG. 4 describedabove an indication of EES acknowledgment is included when the sourceEAS 100 transfers information necessary for the AF request message forthe UP path management event notification to the S-EES 100. In anotherexample, there may be a case that the S-EES 100 transmits an indicationfor the AF acknowledgment to be expected to the 3GPP network 40 in orderto ensure stable mobility by itself.

At step 909 (step 9), the S-EES 100 transmits an AF acknowledgmentmessage to the network function (e.g., NEF, SMF, etc.) that hastransmitted the UP path change related notification message at theabove-described step 900, thereby informing that UP pathconfiguration/activation can be performed with the EEC 52 of the UE.

In case where location information of the UE is provided to the EES 100or 200 or the ECS 30 from the 3GPP network 40 in addition to thenotification message for the UP path change event described above inFIGS. 7 to 9 , it is possible to compare the location information of theUE 50 with the EES service area or EAS service area information, andselect an EES or EAS accessible from the location of the UE 50. In thiscase, if the EES service area or the EAS service area is not defined,the location of the UE 50 and the UPF service area may be compared toidentify DNAI information accessible through the UPF to which the UE 50is connectable. By comparing the identified DNAI with the EES DNAI orEAS DNAI, it is possible to select the EES or EAS accessible by the UE50.

While the disclosure has been particularly shown and described withreference to some embodiments thereof, it will be understood by thoseskilled in the art that any change and modification may be made thereinwithout departing from the scope of the disclosure. Accordingly, thescope of the disclosure should not be limited to the describedembodiments and should be defined by claims set forth below and alsotheir equivalents.

FIG. 10 is a diagram illustrating internal function blocks of an edgeapplication server, an edge enabler server, or an edge configurationserver 30 according to various embodiments of the disclosure.

Referring to FIG. 10 , it may be any one of the EASs 101, 102, and 201,the EESs 100 and 200, or the ECS 30 described in the disclosure.Referring to FIG. 10 , a network interface 1013 may transmit/receive asignal or a message within the edge data network or with the 3GPPnetwork 300 or 40.

A controller 1011 may perform the above-described operations. Forexample, when the configuration of FIG. 10 is the EAS, not only anoperation for providing an edge application service, but also controlaccording to transmission and reception of a signal described in thedisclosure and operations corresponding to case of receiving acorresponding signal/message may be performed. In another example, whenthe configuration of FIG. 10 is the EES, not only operations for UPFrelocation according to the movement of the UE, but also variouscontrols described above and controls for transmission/reception ofsignals/messages may be performed. In still another example, when theconfiguration of FIG. 10 is the ECS, the controller 1011 may receive adiscovery request of EAS and/or EES from a specific node in the edgecomputing system and/or a specific node of the 3GPP network and performcontrols for corresponding retrieval and provision of information. Inaddition, when the configuration of FIG. 10 is the ECS, controlsaccording to the above-described embodiments of FIGS. 3 to 9 may beperformed.

A memory 1012 may store a program and various kinds of controlinformation required by the controller 1011, and may also store variouskinds of information described in the disclosure.

The EAS, the EES, or the ECS may further include various interfaces forconnection with an operator in addition to the configuration describedabove. In the disclosure, there is no particular limitation on such anadditional configuration.

INDUSTRIAL APPLICABILITY

The disclosure can be used in case of providing an MEC service.

The invention claimed is:
 1. A method by an edge enabler server (EES) ofa mobile edge computing (MEC) system for interacting with a mobilecommunication network to provide an edge computing service to a userequipment (UE), the method comprising: subscribing to a user plane (UP)path change event at an edge application server (EAS); determining anapplication context relocation (ACR) based on receiving a UP pathmanagement event notification from the mobile communication network incase of subscribing to the user plane path change event for the EAS;transmitting, to the EAS, an ACR request message; receiving, from theEAS, an EAS response message; and in response to receiving the EASresponse message from the EAS, transmitting an application function (AF)acknowledgment message to a first node of the mobile communicationnetwork, wherein the EAS response message corresponds to a case that anindication of EAS acknowledgment is received from the EAS whensubscribing to the UP path change event.
 2. The method of claim 1,wherein subscribing to the user plane path change event includes:receiving, from the EAS, a subscribe request message requesting a UPpath change event management for the UE, in response to the subscriberequest message, checking occurrence of the user plane path managementevent for the UE with the first node of the mobile communicationnetwork, and transmitting a subscribe response message to the EAS, andwherein the subscribe request message for the UE is a message forapplication context relocation.
 3. The method of claim 2, wherein thesubscribe request message is a message requesting a notification of UPpath change detection according to mobility of the UE to which the EASprovides edge computing service traffic.
 4. The method of claim 3,wherein the subscribe request message includes a subscription type andthe indication of EAS acknowledgment, and wherein the subscription typeincludes an indication of at least one of an early notification and alate notification.
 5. The method of claim 4, wherein the checkingoccurrence of the user plane path management event for the UE furtherincludes: transmitting a subscribe request message for the UP pathmanagement event notification to the first node of the mobilecommunication network, and wherein the subscribe request message for theUP path management event notification includes an indication of “anapplication function (AF) acknowledgment to be expected”.
 6. The methodof claim 1, wherein the first node of the mobile communication networkis a session management function (SMF) device.
 7. The method of claim 1,further comprising: receiving, from the EAS, an EAS profile when the EASis registered, wherein the EAS profile includes information indicatingthat the EAS supports application context transmission.
 8. A method byan edge application server (EAS) of a mobile edge computing (MEC) systemfor interacting with a mobile communication network to provide an edgecomputing service to a user equipment (UE), the method comprising:subscribing to a user plane (UP) path change event with an edge enablerserver (EES) connected to the EAS; transmitting, to the EES, anapplication context relocation (ACR) request message; and receiving,from the EES, an EAS response message, wherein the EAS response messagecorresponds to a case that an indication of EAS acknowledgment istransmitted to the EES when subscribing to the UP path change event. 9.The method of claim 8, wherein the subscribing to the user plane pathchange event includes: transmitting, to the EES, a subscribe requestmessage requesting a UP path change event management for the UE, andreceiving, from the EES, a subscribe response message, and wherein thesubscribe request message for the UE is a message for applicationcontext relocation.
 10. The method of claim 9, wherein the subscriberequest message is a message requesting a notification of UP path changedetection according to mobility of the UE to which the EAS provides edgecomputing service traffic.
 11. The method of claim 9, wherein thesubscribe request message includes a subscription type and theindication of EAS acknowledgment, and wherein the subscription typeincludes an indication of at least one of an early notification and alate notification.
 12. The method of claim 9, further comprising:transmitting, to the EES, an EAS profile when the EAS is registered,wherein the EAS profile includes information indicating that the EASsupports application context transmission.
 13. An edge enabler server(EES) apparatus for providing an edge computing service to a userequipment (UE) in a mobile edge computing system, the apparatuscomprising: a network interface is configured to communicate with anedge computing system or a mobile communication system; a memoryconfigured to store information; and at least one processor, wherein theat least one processor is configured to: subscribe to a user plane (UP)path change event of an edge application server (EAS) through thenetwork interface, determine an application context relocation (ACR)based on receiving a UP path management event notification from themobile communication network through the network interface in case ofsubscribing to the user plane path change event for the EAS, transmit,to the EAS, an ACR request message through the network interface,receive, from the EAS, an EAS response message through the networkinterface, and transmit an application function (AF) acknowledgmentmessage to a first node of the mobile communication network through thenetwork interface in response to receiving the EAS response message fromthe EAS, wherein the EAS response message corresponds to a case that anindication of EAS acknowledgment is received from the EAS whensubscribing to the UP path change event.
 14. The apparatus of claim 13,wherein the at least one processor is configured to, when subscribing tothe user plane path change event: receive, from the EAS, a subscriberequest message requesting a UP path change event management for the UE,in response to the subscribe request message, check occurrence of theuser plane path management event for the UE with the first node of themobile communication network, and transmit a subscribe response messageto the EAS, wherein the subscribe request message for the UE is amessage for application context relocation.
 15. The apparatus of claim14, wherein the subscribe request message is a message requesting anotification of UP path change detection according to mobility of the UEto which the EAS provides edge computing service traffic.
 16. Theapparatus of claim 14, wherein the subscribe request message includes asubscription type and the indication of EAS acknowledgment, and whereinthe subscription type includes an indication of at least one of an earlynotification and a late notification.
 17. The apparatus of claim 14,wherein the at least one processor is configured to, when checkingoccurrence of the user plane path management event for the UE, transmita subscribe request message for the UP path management eventnotification to the first node of the mobile communication networkthrough the network interface, and wherein the subscribe request messagefor the UP path management event notification includes an indication of“an application function (AF) acknowledgment to be expected”.
 18. Theapparatus of claim 13, wherein the first node of the mobilecommunication network is a session management function (SMF) device. 19.The apparatus of claim 13, wherein the at least one processor isconfigured to receive, from the EAS, an EAS profile through the networkinterface when the EAS is registered, and wherein the EAS profileincludes information indicating that the EAS supports applicationcontext transmission.
 20. An edge application server (EAS) apparatus forproviding an edge computing service to a user equipment (UE) in a mobileedge computing system, the apparatus comprising: a network interface isconfigured to communicate with an edge computing system or a mobilecommunication system; a memory configured to store information; and atleast one processor, wherein the at least one processor is configuredto: subscribe to a user plane (IP) path change event with an edgeenabler server (EES) connected to the EAS through the network interface,transmit, to the EES, an application context relocation (ACR) requestmessage through the network interface, and receive, from the EES, an EASresponse message through the network interface, wherein the EAS responsemessage corresponds to a case that an indication of EAS acknowledgmentis transmitted to the EES when subscribing to the UP path change event.21. The apparatus of claim 20, wherein the at least one processor isconfigured to, when subscribing to the user plane path change event:transmit, to the EES through the network interface, a subscribe requestmessage requesting a UP path change event management for the UE, andreceive, from the EES through the network interface, a subscriberesponse message, and wherein the subscribe request message for the UEis a message for application context relocation.
 22. The apparatus ofclaim 21, wherein the subscribe request message is a message requestinga notification of UP path change detection according to mobility of theUE to which the EAS provides edge computing service traffic.
 23. Theapparatus of claim 21, wherein the subscribe request message includes asubscription type and the indication of EAS acknowledgment, and whereinthe subscription type includes an indication of at least one of an earlynotification and a late notification.
 24. The apparatus of claim 20,wherein the at least one processor is configured to transmit, to the EESthrough the network interface, an EAS profile when the EAS isregistered, and wherein the EAS profile includes information indicatingthat the EAS supports application context transmission.